1. Technical Field
The present invention relates to a liquid ejecting head, such as an ink jet type recording head, and a liquid ejecting apparatus that includes the liquid ejecting head. More particularly, the invention relates to a liquid ejecting head that includes a flow path member in which a plurality of flow path component members are stacked and to a liquid ejecting apparatus that includes the liquid ejecting head.
2. Related Art
A liquid ejecting apparatus is an apparatus that is equipped with a liquid ejecting head and that ejects (discharges) various liquids from the ejecting head. Examples of the existing liquid ejecting apparatus are image recording apparatuses such as ink jet type printers and ink jet type plotters. In recent years, the liquid ejecting apparatus is applied to various production apparatuses by utilizing the advantage of being capable of accurately landing very small amounts of liquid at predetermined locations. Examples of such applications include a display production apparatus that produces a color filter of a liquid crystal display and the like, an electrode forming apparatus that forms electrodes of organic electro-luminescence (EL) displays, field emission displays (flat panel displays), etc., and chip production apparatuses that produce biochips (biochemical devices). The recording head for an image recording apparatus ejects an ink in a liquid state, and the color material ejecting head for a display production apparatus ejects solutions of color materials of red (R), green (G), and blue (B). Furthermore, the electrode material ejecting head for an electrode forming apparatus ejects an electrode material in a liquid state, and the bioorganic material ejecting head for a chip production apparatus ejects a solution of a bioorganic material.
The liquid ejecting head introduces a liquid from a liquid supply source in which the liquid is stored, and ejects the liquid in the form of droplets from the nozzles by driving drive elements such as piezoelectric elements, heating elements, etc. A certain liquid ejecting head includes liquid flow paths constructed of a plurality of stacked component parts. For example, in a liquid ejecting head described in JP-A-2015-051623, flow path members that include a first flow path member, a filter, and a second flow path member are housed within an upper/lower case member that includes an upper case member and a lower case member. Furthermore, a seal member (bush) made of an elastic material is provided between a lower case member and a flow path portion that includes the upper case member and a flow path member. This seal member provides liquid-tight communication between a flow path of a flow path portion side and a flow path of a lower case member side via a through opening of the seal member. In this construction, the seal member is provided with an atmospherically open path that provides communication between a space on an inner periphery side of the seal member and the atmosphere on an outer periphery side of the seal member. Therefore, a space on a lower side of the seal member and a space formed between the seal member and the flow path portion are open to the atmosphere through the atmospherically open path. This atmospherically open path is formed by a thin groove formed on an upper surface of an annular seal site of the seal member and the flow path member in close contact with the upper surface of the annular seal site.
In the foregoing construction, the upper case member is merely fixed to the lower case member by performing, for example, screwing or crimping, from a lower portion of the case. Therefore, gas tightness and liquid tightness of the interior of the upper/lower case member are not secured. Furthermore, because a common elastomer used for the seal member is not an elastomer enhanced in gas barrier property, moisture (a solvent component) in a liquid flow path passes in the form of vapor through the material of the seal member in addition to the foregoing atmospherically open path and diffuses into the atmosphere. Therefore, there is a problem that the thickening (viscosity increase) of the liquid in the liquid flow path of the flow path member in particular progresses.